Phosphonio carboxylates



United States Patent 3,504,024 PHOSPHONIO CARBOXYLATES Francis L. Diehl and Howard F. Drew, Wyoming, and Robert G. Laughlin, Springfield Township, Hamilton County, Ohio, assignors to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Filed Aug. 23, 1966, Ser. No. 574,470

Int. Cl. C0715 9/54 US. Cl. 260526 2 Claims ABSTRACT OF THE DISCLOSURE Phosphonio carboxylates are disclosed having effective detergency in cool water laundering and the following general formula:

R2 R 1 (OHz)nCO2 R is C -C alkyl; R and R are each C -C alkyl or hydroxyalkyl; n ranges from 3 to 5.

This invention relates to phosphonio carboxylates and detergent compositions containing same which are especially efl ective in cool water. The term cool water as used in describing this invention is intended to mean aqueous Washing solutions having a temperature within a range of from about 40 F. to about 95 F. This temperature characterization more generally is intended to mean temperatures substantially below those which are commonly associated with the usual household parlance of hot water.

Some garments or fabrics cannot be washed in hot water, i.e., say in excess of about 110 F., without running the risk of damaging the material by shrinkage or altering the handle or feel of the fabric or by adversely affecting dyes or by increasing wrinkling in washand-wear or minimum care garments. For such laundering situations fabric and material manufacturers recommend the use of cool water. Conventional detergents, however, are known to be less effective as cleaning agents, i.e., removing soil, in cool aqueous solutions. There is no question that the presently available detergent compositions can be used under such circumstances but with varying degrees of successful cleaning results. To compensate for the poorer cleaning performance, consu-mers are generally inclined to use excessive amounts of the detergent compositions. Such economic waste is unfortunate but has been necessary prior to the present invention due to the lack of detergent compositions which are specially formulated to be effective cleaning agents in cool water.

It is an object of this invention to provide novel detergent compounds and detergent compositions containing same which are especially eifective in cleaning soiled fabrics in cool aqueous washing solutions and a method for using such a composition in laundering with cool water.

Other objects will be readily apparent to those skilled in the art from a review of the following detailed description of the present invention.

This object of the present invention is achieved with novel phosphonio carboxylate detergent compounds having the general formula noted below and built detergent compositions containing same:

R is an alkyl group containing from 10 to 18 carbon atoms; R and R are each alkyl or hydroxy alkyl groups containing from 1 to 4 carbon atoms; n is 3, 4 or 5. The detergent compositions of this invention contain a phosphonio carboxylate of this class and a water soluble inorganic alkaline builder salt, an organic alkaline sequestrant builder salt or mixtures thereof, the ratio of weight of the detergent to the builder salt being in the range of from about 4:1 to 1:20.

It has been surprisingly discovered that certain phosphonio carboxylate compounds having the formula set forth above possess unusually effective cleaning power in aqueous solutions having the cool temperatures defined above. These unexpected cleaning properties of the zwitterionic compounds of this invention are demonstrated by the experimental data presented below. Of the phosphonio carboxylate detergent compounds described herein, best cool water celaning results are obtained when R is dodecyl, R and R are each methyl and n is 3, i.e., 4-(P,P dimethyl-P-dodecyl phosphonio)butyrate.

The phosphonio carboxylate compounds to which the present invention pertains can be prepared by reacting a suitable tertiary phosphine with a w-ChlOIO (or w-bromo) carboxylate and then saponifying the resulting ester.

Equations (unbalanced) illustrating this synthesis are shown below; in the equations R R R :and n have the same definitions as noted above and X is chloro or bromo:

The base (MOH) can be NaOH or KOH. The solvent can be a lower monohydric alcohol such as isopropanol in which the alkali metal halide (MX) is insoluble. The temperature of the first reaction can range from 50 to 120C. The time suflicient to achieve complete reaction is about 5 days when X above is chloro. The temperature of the saponification can range from 25 to 100 C. The usual by-product is a sodium or potassium chloride or bromide.

Phosphonio acetates and propionates can be prepared, but it has been found that such compounds are unstable and therefore unsuitable as detergents.

The following example illustrates the preparation of the compounds of this invention.

EXAMPLE I 14.6 grams (0.017 mole) of methyl 4-chlorobutyrate (Cl(CH CO CH and 50 ml. of methanol were placed in a 500 ml. flask equipped with a condenser, thermometer and a stopper. These two ingredients were mixed with a 'mechanical stirrer and were maintained under argon gas under positive pressure.

22.4 grams (0.0974 mole) of dimethyldodecylphosphine were added from a syringe under the surface of the mixture of 'y chlorobutyrate and methanol. The resulting reaction mixture was heated to reflux temperature; refluxing continued for 5 days. The mixture was then cooled to 20 C. 'with tap water and the methanol evaporated in vacuo. The resulting ester was saponified with 7.06 grams of aqueous KOH (0.107 mole) in 250 ml. of isopropanol, maintaining the temperature below 30 C. The reaction mixture was permitted to stand for 3 /2 hours. The KCl in the saponified mixture precipitated from the isopropanol in crystalline form, was filtered off and the solvent evaporated to leave 4-(P,P dimethyl-P-dodecyl phosphonio butyrate.

Other phosphonio carboxylates of the class of compounds of this invention can be prepared in a similar fashion using appropriate reactants to form the particular compounds desired. For example, S-chloro (or bromo) pentanoate or 6-chloro (or bromo) hexanoate esters can be employed to prepare phosphonio carboxylates wherein n in the general formula is 4 or 5. The starting phosphine material can likewise be selected to prepare the desired phosphonio carboxylate. For example, the following phosphines can be employed with any of the w chloro or w bromo butyrates, pentanoate's or hexanoates:

diethyltetradecylphosphine bis( l-hydroxymethyl)hexadecyl phosphine dipropyldecylphosphine dimethyloctadecylphosphine hydroxyethyl methyl dodecyl phosphine While the class of phosphonio carboxylate compounds just described can be employed alone as cool water detergent compounds on easily cleanable materials, more outstanding performances are obtained when they are mixed with other ingredients which enhance or build the cleaning power of detergent compounds, i.e., so-called builders or detergency-enhancing compounds. Such built or heavy-duty detergency is essential with hard-to-clean fabrics such as cotton. According to the present invention, therefore, the phosphonio carboxylate detergent compounds are preferably used in conjunction with such other ingredients which substantially improve cleaning power. While the term builder is used herein in its singular form, the term is intended to cover mixtures of such compounds also.

The present invention also pertains to detergent compositions consisting essentially of a Water soluble inorganic alkaline builder salt or a water soluble organic alkaline sequestrant builder salt, or mixtures thereof, and a member of the class of phosphonio carboxylate detergent compounds having the general formula described above, which composition consists essentially of the detergent compound and a builder material in a ratio by weight of detergent to builder of about 4:1 to about 1:20. The preferred ratio of the detergent to builder is 1:1 to about 1:10. The ratios and percentages referred to herein are all by weight unless otherwise noted.

The built detergent compositions of this invention can be prepared as granular, tablet, or liquid compositions and perform effectively. Within the above detergent to builder ratio range, granular and tablet compositions offering outstanding cool water washing performance can contain from 4% to 50% by weight of the phosphonio carboxylate detergent compound, the balance comprising essentially a selected builder material or mixtures of builders and any optional ingredients employed. Preferred granular and tablet compositions contain from about to about 35% by weight of the phosphonio carboxylate detergent with the balance comprising the essential builder materials and other ingredients. On the other hand, built liquid detergents prepared according to the present invention have a slightly modified composition to compensate for the requirement of a liquid vehicle. Such liquid compositions can contain from about 2% to 25% by weight of the phosphonio carboxylate detergent, preferably from about 8% to about 18%, with the remainder comprised essentially of builder ingredients, and, of course, a liquid vehicle as described below. The ratio set forth above between the detergent and builder applies equally to all physical forms of the composition.

Water soluble inorgaic alkaline builder salts which can be used in this invention alone or in admixture are alkali metal carbonates, borates, phosphates, polyphosphates, biearbonates and silicates. Ammonium or substituted ammonium, e.g., triethanol ammonium, salts of these materials can also be used. Specific examples of suitable salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium and potassium pyrophosphate, sodium and ammonium bicarbonate, potassium tripolyphosphate, sodium hexaphosphate, sodium sesquicarbonate, sodium orthophosphate and potassium bicarbonate. The preferred inorganic alkaline builders according to this invention are alkali metal tripolyp'hosphates for built granular and tablet compositions and alkali metal pyrophosphates for built liquid compositions. Potassium is the preferred alkali metal used in liquid compositions and sodium finds best application for granular or tablet compositions.

Examples of suitable organic alkaline sequestrant builder salts used in this invention alone or in admixture are alkali metal, ammonium or substituted ammonium, aminocarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(Z-hydroxyethyl)-ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium, potassium and triethanolammonium N-(2-hydroxyethyl)nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable. The alkali metal salts of phytic acid, e.g., sodium phytate are also suitable as organic alkaline sequestrant builder salts (see US. Patent 2,739,942).

Polyphosphonates are also valuable builders in terms of the present invention including specifically sodium and potassium salts of ethane-l-hydroxy-l, l-diphosphonic acid, sodium and potassium salts of methylene diphosphonic acid sodium and potassium salts of ethylene diphosphonic acid, and sodium and potassium salts of ethane-1,1,2-triphosphonic acid. Other examples include the alkali metal salts of ethane-2-carboxy-l,l-diphosphonic acid, hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethane-l-hydroxy-l,1,2-triphosphonic acid, ethane-Z-hydroxy-l,1,2-triphosphonic acid, propane- 1,l,3,3 tetraphosphonic acid, propane-1,1,2,3-tetraphosphonic acid, and propane-l,2,2,3-tetraphosphonic acid.

Besides the builders being used in the form of mixtures it is also possible according to the present invention to use the phosphonio carboxylate compounds of this invention in combination with other cleaning agents such as anionic, nonionic, ampholytic and other zwitterionic organic detergent compounds. When it is desired to use such phosphonio carboxylate compounds in combination with other detergent compounds, they are preferably utilized 'with anionic detergents because of the sudsing characteristics of the latter. The ratio of the phosphonio carboxylate to such other detergent compound is about 10:1 to 1:5. If it is desired to use such a phosphonio carboxylate in admixture with another detergent compound as the active portion of a cleaning composition, the ratio of such a mixture to the builder salt should be within the previously prescribed range of 4:1 to 1:20. A composition prepared along these lines can contain from 4% to of such a mixture and 5% to 85% of a builder salt selected from water soluble inorganic alkaline builder salts, water soluble organic sequestrant builder salts, and mixtures thereof, within the prescribed ratio range. 1

Examples of anionic soap detergents which can be used in admixture with the carboxylate detergent, if desired, are the sodium, potassium, ammonium and alkylolammonium salts of higher detergent range fatty acids (C -C Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap. Examples of suitable anionic organic non-soap detergents in the form of their water soluble salts are: alkylglycerylethersulfonates; alkyl sulfates; alkyl monoglyceride sulfate; sodium salt of sulfonated a tridecene; potassium N- methyl-N-lauroyl tauride; triethanolam-monium tetrapropylbenzene sulfonate; sodium (linear) dodecyl benzene sulfonate.

Examples of nonionic organic detergents which can be used in the compositions of this invention, if desired, are: polyethylene oxide condensates of alkylphenols wherein the alkyl group contains from 8 to 15 carbon atoms (e.g., t-octylphenol) and the ethylene oxide is present in a molar ratio of ethylene oxide to alkylphenol in the range of 8:1 to 20:1; condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine wherein the molecular weight of the condensation products ranges from 5,000 to 11,000; the condensation products of from about 5 to 30 moles of ethylene oxide with one mole of a straight or branched chain aliphatic alcohol containing from 8 to 18 carbon atoms, e.g., condensation product of 6 moles of ethylene oxide with one mole of lauryl alcohol; higher alkyl dilower alkyl amine or phosphine oxides, e.g., dodecyldimethylarnine oxide or dodecyldimethyl phosphine oxide; alkyl methyl sulfoxides such as dodecyl methyl sulfoxide.

Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18'carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate, 3 (N methyl-N-hexadecyl amine) Z-hydroxy propane-l-sulfonate and its dodecyl homolog, sodium S-dodecylaminoprdpane sulfonate, do decyl-beta-alanine, N-alkyltaurines such as the one prepared reacting the dodecylamine with sodium isethionate according to the teaching of United States Patent No. 2,658,072, N-higher alkyl aspartic acids such as those produced according to the teaching of United States Patent No. 2,438,091, and the products sold under the trade name Miranol and described in United States Patent No.

Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium and ternary sulfonium compounds, in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from 10 to 18 carbon atoms and one contains an anionic water solubilization group, e.g., carboxy, sulfo, or sulfato. Examples of compounds falling within this definition are: 3 (N,N dimethyl-N-hexadecylammonio)-2-hydroxypropane-l-sulfonate and the corresponding dodecyl and tetradecyl homologs and 3-(N,N-dimethyl-N-dodecylammonio)-propane-1-sulfonate vand the corresponding hexadecyl and tetradecyl homologs.

The discovery that the compositions containing members of the class of compounds described in this invention show exceptional cool water detergency was unpredictable in view of the fact that there is, as yet, virtually no generally accepted theory or background information on the mechanics of cool water detergency. Moreover, cleaning agents such as sodium tallow alcohol sulfate, or sodium doceylbenzenesulfonate, for example, which are good hot water (130140 F.) detergent compounds exhibit a minimum of cleaning activity in cool water. One would be led to assume that the phosphonio carboxylate compounds of the present invention should be, comparatively speaking, as poor as any other conventional detergent compounds when used in cool water; certainly there is no reason to expect that they would behave otherwise. As has been discovered, however, the compositions containing the phosphonio carboxylate compounds of this invention are more effective in cool water thansome of the commonly used commercially available detergent compositions are in hot water. It can, therefore, be seen that the structure of a given detergent compound which is effective in hot water has little or no discernible relation to the effectiveness of such compounds in cool water.

It has also been found that maximum cleaning occurs with the compositions of this invention when the pH of the washing solution, at cool water temperatures as herein defined is within the range of from about 8 to about 12 with the preferred pH range being 9.5 to 11.5. Using normal amounts of water for washing, the desired pH of the solution can be obtained by incorporating into the compositions of this invention a normal amount of a strongly alkaline material such as sodium silicate, i.e., up to about 10% by weight. The silicate acts as a buffer and also as a corrosion inhibitor.

A laundering method incorporating the discovery of the present invention can be practiced in a number of different ways. Preferably thewashing step is followed by rinsing and drying the fabrics. The washing solution can be prepared by adding the granular, tablet or liquid detergent composition prepared according to this invention to any container which contains cool water at a temperature ranging from about 40 F. to about F., usually about 80 F. The detergent composition concentration in solution can range from about .05% to .50% by total Weight in the usual washing operation and should be added in sufficient amount to provide a concentration of at least 0.005% of the phosphonio carboxylate detergent compound. The fabrics can be added to the container or washer before or after the washing solution is added. As is usual in a washing step, the fabrics are then agitated in the detergent solution. While the period of time may vary, an automatic agitator type washer, generally employs a washing cycle which ranges from 8 to 15 minutes. In special situations, such as hand washing in basins, pools or streams, higher composition concentrations can be employed including solutions or pastes of up to 5%, 25% or even 50% and higher.

After the washing step, the washing liquor is drained off or the fabrics are separated from the liquor and thereafter the fabrics are rinsed in clean water. The fabrics can be rinsed as many times as desired in order to insure that washing liquor is removed. Using an automatic washer, it has been found that one or more spray rinses and one deep rinse are usually suflicient for this purpose. Between and after rinsing steps, the bulk of the rinse water is usually drawn from or spun out of the fabrics. After rinsing, the fabrics are dried. Although rinsing and drying are usual and desirable steps, the important advantage of the invention is achieved in the washing step.

The surprisingly effective cool water performance characteristics of the phosphonio carboxylate compounds described herein are demonstrated by conducting the following tests.

' Naturally soiled fabric swatches (desized cotton print cloth) were washed for ten minutes in an aqueous solution of a detergent composition having a pH of 10 and containing 7 grains equivalent CaCO hardness per gallon. Detergent compositions were prepared containing only basic essentials, i.e., a detergent compound and a builder compound. The detergent compounds were respectively (l) a representative phosphonio carboxylate and (2) sodium tetrapropylenebenzene sulfonate (ABS); the builder compound in each composition was sodium tri polyphosphate. The phosphonio carboxylate compound was 4-(P,P-dimethyl, P-dodecyl phosphonio) butyrate (DMDPB). By using the same builder compound in each composition, any variations in cleaning performance could be directly attributed to the specific detergent being evaluated. The concentration by weight in the washing solution of the detergent compound was .03%; the concentration of the builder was .06%.

These two compositions were compared in two separate comparisons for their soil removal properties, the phosphonio carboxylate in a Washing solution at 80 F. and the ABSin a washing solution at F. Soil removal,

Compound Temperature, F. Soil removal ABS 140 63. 1% and 62. 1% DMDPB 80 63.8% and 62. 8%.

The phosphonio carboxylate detergent compound gave results in these tests, in Water at 80 P. which were superior to the results obtained with a formula wherein sodium tetrapropylenebenzenesulfonate (ABS) was used as a cleaning agent in a washing solution having a temperature of 140 F. Sodium tetrapropylenebenzenesulfonate is widely regarded as a standard for comparison. Compositions which perform as good as or better than ABS at 140 F. generally can find application and commercial acceptance as detergent formulations. In situations such as the present invention where superior cleaning is obtained with different compounds at low temperatures, i.e., 80 F., the results are even more remarkable.

The same superiority of the phosphonio carboxylate compound at 80 F. over ABS at 140 F. was demonstrated in a similar Washing test employing soiled mens white dress shirts where the collars and cuffs were used as the basis for comparing cleaning ability of composi' tions employing these two detergent compounds.

Substantially the same performance advantages are observed by the housewife when doing the home laundry in water ranging from 40 to 95 F., particularly laundering cotton goods. Woolens, synthetic fibe'rs and washand-wear garments washed in the same manner are cleaned as efliciently when washed according to the process of this invention and using the compositions of this invention as they would be if they were' washed in conventional detergent compositions at hot water temperatures, yet a minimum of shrinkage and wrinkling takes place and the color and feel of the fabric is preserved to a greater extent.

While the compositions of this invention are outstandingly effective in water at a temperature ranging from 40 F. to 95 F. the preferred temperature range is about 60 F. to 90 F. Below about 60 F. it has been found that the granular detergent compositions of this invention are somewhat slower to dissolve, consequently it is preferred to use liquid compositions at such lower temperatures.

The following compositions further illustrate the manner in which the invention can be practiced; they provide improved cool water detergency characteristics similar to that demonstrated in the soil removal comparison set forth above. The pHs of each of the compositions in aqueous solutions ranged from 9.5 to 11.5 at concentrations of about 0.25%. Included are both liquid and granular formulations. Mixtures of the phosphonio carboxylates and other detergents can be used. The examples are not to be construed as limiting the scope of the invention claimed hereinafter. These compositions are useful in automatic washers and conventional type washers employing cool water, 40 F. to 95 F., as well as hand washing operations:

8 EXAMPLE III Compressed granules-tablet Percent 4-(P,P-dipropyl, P-tetradecyl phosphonio) butyrate 31 Tetra sodium pyrophosphate 52 Trisodium phosphate l0 Moisture 7 EXAMPLE IV Solid-granules Percent 5-(P,P,bis(Z-hydroxyethyl), P-hexadecyl phosphonio) pentanoate 32 Trisodium ethane-l-hydroxy-l,1,2-triphosphonate 64 Moisture 4 EXAMPLE V Solid-granules Percent 3-(N,N dimethyl N hexadecyl ammonio)-propane-1- sulfonate 20 6-(P,P,dipropyl, P-dodecyl phosphonio)-hexanoate 25 4-(P,P-dimethyl, P-hexade'cyl phosphonio) butyrate 20 Sodium tallow alcohol sulfate 10 Trisodium ethane-l-hydroxy-l,l-diphosphonate 20 Sodium tripolyphosphate 10 Sodium nitrioltriacetate 10 Sodium sulfate 8 Sodium silicate (Na O:SiO =1:2.5) 11 Moisture 11 EXAMPLE VII Liquid Percent 4-(P,P-dimethyl, P-decyl phosphonio) butyrate 5.0 Sodium salt of S0 sulfonated 1:1 weight mixture of dodecene' and a tetradecene 10.0 Tetrapotassium pyrophosphate 19.0 Sodium silicate (Na O:SiO =1:1.6) 3.8 Potassium toluene sulfonate 8.5 Carboxymethyl hydroxyethyl cellulose .3 Water Balanc EXAMPLE VIII Liquid Percent 5- (P,P,bis(Z-hydroxypropyl),P-dodecyl phosphonio) pentanoate Sodium (linear) dodecyl benzene sulfonate' 6.0 Tetrapotassium propane-1,1,3,3-tetraphosphonate 20.0 Sodium silicate (Na O:SiO =1:1.6) 3.8 Potassium toluene sulfonate 8.5 Carboxymethyl hydroxymethyl cellulose .3 Water Balanc EXAMPLE IX Solid-granules Percent 4(P,P-dipropyl, P-dodecyl phosphonio)butyrate 5 Condensation product of 10 moles of ethylene oxide and one mole of tallow fatty alcohol 5 Sodium (linear) tridecyl benzene sulfonate 10 Dodecyldimethyl phosphine oxide 5 Coconut oil soap 5 Sodium tripolyphosphate 50 Tetrasodium ethylene diamine' tetraacetate 20 It will be appreciated that the phosphonio carboxylate compounds used in the present invention can be incorporated into many other liquid or granular detergent compositions with suitable adjustments being made in the other components.

Materials which are considered normal and desirable additives in liquid or granule detergent compositions can be added to the compositions of this invention without adversely affecting or modifying basic cleaning characteristics. For example, a tarnish inhibitor such as benzotriazole or ethylene thiourea may be added in amounts up to about 1%. Fluorescers, perfume, bleaching agents, color, antiredeposition agents, antibacterial agents, thickening agents, opacifiers, and blending or viscosity control agents, while not essential in the compositions of this invention, may also be added.

While the present invention finds exceptional application in cool water Washing situations, the compositions described herein can also be used in conjunction with warm and hot water.

What is claimed herein is:

1. A phosphonio carboxylate compound of the following general formula:

R is an alkyl group containing from 10 to 18 carbon atoms; R and R are each alkyl or hydroxy alkyl groups containing from 1 to 4 carbon atoms; wherein n ranges from 3 to 5.

2. 4-(P,P-dimethyl, P-dodecyl phosphonio) butyrate.

References Cited UNITED STATES PATENTS 3/1964 Pare et al. 260526 OTHER REFERENCES Bissing: Journal of Organic Chemistry, vol. 30, pp. 12968 (April 1965).

JAMES A. PATTEN, Primary Examiner US. Cl. X.R. 

